This is a selectively annotated list of the most prominent or important members of the Socialist Party of America (1901–1972).
Summary list
Key: * Went on to join the Communist Party, Communist Labor Party of America or Workers Party of America ISS A founder or key member of the Intercollegiate Socialist Society, 1905, later League for Industrial Democracy IWW A founder of the Industrial Workers of the World, 1905. SDL Left to found the Social Democratic League of America, 1917. SDF Left to found the Social Democratic Federation, 1936. IPN Left to found the Independent Party of Norwalk, 1951 SDUSA Continued into Social Democrats, USA, 1973 SPUSA Went on to join the Socialist Party USA, 1973 DSOC Went on to join the Democratic Socialist Organizing Committee, 1973, later Democratic Socialists of America
Martin Abern * Devere Allen Elmer Allison * Harry Ault J. Mahlon Barnes David P. Berenberg Victor L. Berger Barney Berlyn Allan L. Benson Ella Reeve Bloor * Nikolai Bukharin Roy E. Burt Frank Bohn IWW Earl Browder* Jack Carney * James P. Cannon * John C. Chase Travers Clement Joseph Coldwell James Connolly Eugene V. Debs IWW Nicholas Dozenberg * David Dubinsky Max Eastman * J. Louis Engdahl Elizabeth Gurley Flynn * William Z. Foster * Louis Fraina * Joseph Freeman * Irving Freese IPN Samuel Friedman SPUSA Julius Gerber Adolph Germer Arturo Giovannitti Benjamin Gitlow * Carl Haessler * Emanuel Haldeman-Julius SDL Job Harriman Michael Harrington DSOC Hubert Harrison Max S. Hayes Bill Haywood IWW Emil Herman George D. Herron Morris Hillquit ISS Daniel Hoan Darlington Hoopes SPUSA Jessie Wallace Hughan ISS Haim Kantorovitch David Karsner Helen Keller Charles H. Kerr George R. Kirkpatrick Alexandra Kollontai Antoinette Konikow * Frederick Krafft Maynard C. Krueger William F. Kruse * Leo Krzycki Harry W. Laidler ISS Algernon Lee ISS, SDF Lena Morrow Lewis SDF Walter Lippman Jack London ISS George Lunn Theresa S. Malkiel Mary Marcy James H. Maurer SDF Jasper McLevy SDF David McReynolds SPUSA Walter Thomas Mills Tom Mooney Thomas J. Morgan Gustavus Myers Scott Nearing Reinhold Niebuhr Santeri Nuorteva Kate Richards O'Hare James Oneal SDF Mary White Ovington Joseph Arthur Padway Jacob Panken Patrick L. Quinlan A. Philip Randolph SDF, SDUSA John Reed * Victor Reuther DSOC Walter Reuther Charles Edward Russell Bayard Rustin SDUSA Carl Sandburg Margaret Sanger Roland D. Sawyer Clarence Senior Max Shachtman Abraham Shiplacoff Upton Sinclair ISS John W. Slayton John Spargo SDL Seymour Stedman Charles P. Steinmetz A.M. Stirton J.G. Phelps Stokes ISS, SDL Rose Pastor Stokes * Maurice Sugar Norman Thomas Henry M. Tichenor Hermon F. Titus Gus Tyler Ernest Untermann Charles H. Vail Baruch Charney Vladeck Alfred Wagenknecht * Louis Waldman SDF Julius Wayland George W. Woodbey John M. Work Frank P. Zeidler SPUSA
Annotated list
Key: * Went on to join the Communist Party, Communist Labor Party of America or Workers Party of America ISS A founder or key member of the Intercollegiate Socialist Society, 1905, later League for Industrial Democracy IWW A founder of the Industrial Workers of the World, 1905. SDL Left to found the Social Democratic League of America, 1917. SDF Left to found the Social Democratic Federation, 1936. SDUSA Continued into Social Democrats, USA, 1973 SPUSA Went on to join the Socialist Party USA, 1973 DSOC Went on to join the Democratic Socialist Organizing Committee, 1973, later Democratic Socialists of America
Martin Abern * Devere Allen Elmer Allison * E.B. "Harry" Ault J. Mahlon Barnes David P. Berenberg Victor L. Berger, Congressman from Milwaukee Barney Berlyn Allan L. Benson, 1916 candidate for Vice-President Ella Reeve Bloor * Roy E. Burt Frank Bohn IWW Earl Browder *, Communist Party leader and presidential candidate James P. Cannon *, leader of the Communist Party and Socialist Workers Party Jack Carney Travers Clement Joseph Coldwell James Connolly, Irish labor and nationalist leader Eugene V. Debs IWW, labor organizer, Presidential candidate David Dubinsky, labor leader Max Eastman *, writer J. Louis Engdahl William M. Feigenbaum, New York assemblyman 1918 Elizabeth Gurley Flynn *, IWW and Communist leader William Z. Foster *, Communist leader and presidential candidate Louis Fraina * Joseph Freeman * Samuel Friedman, Vice-presidential candidate Charles B. Garfinkel, New York assemblyman 1918, temporary chairman of the NYC central committee SPA in 1935 after Old Guard was expelled Julius Gerber Adolph Germer Arturo Giovannitti Benjamin Gitlow * Carl Haessler * Emanuel Haldeman-Julius SDL Job Harriman, Vice-presidential candidate Michael Harrington DSOC, author Hubert Harrison Max S. Hayes, labor leader Bill Haywood IWW Emil Herman George D. Herron Morris Hillquit ISS, labor lawyer, New York mayoral candidate Daniel Hoan, mayor of Milwaukee Darlington Hoopes SPUSA Jessie Wallace Hughan ISS Henry Jager, NY assemblyman 1921 Haim Kantorovitch William KarlinSDF, lawyer, NY assemblyman 1918 Helen Keller Charles H. Kerr, publisher George R. Kirkpatrick Antoinette Konikow * Frederick Krafft Maynard C. Krueger William F. Kruse * Leo Krzycki, chairman Harry W. Laidler ISS Algernon Lee ISS, SDF Walter Lippman, journalist Jack London ISS Meyer London, Congressman from New York City George R. Lunn, mayor of Schenectady, New York Theresa S. Malkiel Mary Marcy James H. Maurer SDF Jasper McLevy SDF, mayor of Bridgeport, Connecticut David McReynolds SPUSA, peace advocate, SPUSA presidential candidate Herbert M. Merrill, secretary of the SPA-NY, first Socialist New York assemblyman (1912) Walter Thomas Mills Tom Mooney Thomas J. Morgan Gustavus Myers Scott Nearing Reinhold Niebuhr, theologian Santeri Nuorteva Kate Richards O'Hare James Oneal SDF Mary White Ovington, co-founder of the NAACP Joseph Arthur Padway Jacob Panken, New York municipal judge A. Philip Randolph SDF, SDUSA, labor and civil rights leader John Reed *, author Victor Reuther DSOC, labor organizer Walter Reuther, labor organizer Elmer Rosenberg, New York assemblyman 1918 Charles Edward Russell, writer Bayard Rustin SDUSA, civil rights organizer Carl Sandburg, poet Margaret Sanger, advocate of family planning Roland D. Sawyer Edmund Seidel, New York state senator 1921–1922 Clarence Senior Max Shachtman Abraham I. Shiplacoff, NY assemblyman 1916, 1917, 1918 Upton Sinclair ISS, writer, organized End Poverty in California (EPIC) John W. Slayton John Spargo SDL, writer Seymour Stedman Charles P. Steinmetz, physicist A.M. Stirton, publisher of The Wage Slave, candidate for governor in Michigan in 1908 J.G. Phelps Stokes ISS, SDL, social reformer Rose Pastor Stokes *, social reformer Maurice Sugar Norman Thomas, peace advocate, Presidential candidate Henry M. Tichenor Hermon F. Titus Gus Tyler, writer and labor leader Ernest Untermann Charles H. Vail Baruch Charney Vladeck Alfred Wagenknecht * Louis Waldman SDF Julius Wayland, publisher of The Appeal to Reason Joseph A. Whitehorn, lawyer, New York assemblyman 1917, 1918 George W. Woodbey, preacher and African-American leader John M. Work Frank P. Zeidler SPUSA, mayor of Milwaukee, SPUSA presidential candidate